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Iron Butterfly Ironweed Vernonia lettermannii 'Iron Butterfly'

Phonetic Spelling
ver-NON-ee-uh let-ter-MAH-nee-eye
Description

Iron butterfly ironweed is an ironweed cultivar that is grown for its mounding habit and showy long-lasting bright purple-violet flowers. This cultivar was created to accentuate a compact habit, rapid growth rate, and long bloom period. It grows to a height of 24 to 36 inches tall and 18 to 24 inches wide. It is a member of the Asteraceae family.

The genus name, Vernonia, honors an English botanist, William Vernon. The epithet, lettermanii, honors, an American botanist, George W. Letterman.

The plant is dense and multi-branched, and the foliage is fine and thread-like. Many frilly aster-like or disc flowers appear in summer at a time when other flowers are giving out to provide the bees and butterflies with nectar. They will flock to this plant! The foliage is attractive even when not in bloom, adding a finer texture to the garden. 

Grow this plant in average well-drained soils in full sun to light shade. It is drought tolerant once established and poor soil tolerant so do not over-fertilize. It is recommended to cut this plant back early in the season to prevent the stems from flopping over. Seedlings of this plant are taller with bigger and bolder leaves. To prevent seedlings from developing, trim the flowers as they go to seed. Leave the stems intact during the winter and cut to the ground in late winter or early spring. 

Use the iron butterfly ironwood to add texture and color to the late-season garden. Consider using this plant in a rock garden, drought-tolerant garden, or as a border in a pollinator garden. 

Quick ID Hints:

  • grows 24 to 36 inches tall and 18 to 24 inches wide, dense, and multi-branched
  • foliage fine, thread-like
  • aster-like flowers of bright purple violet in late summer

Insects, Diseases, and Other Plant Problems: This cultivar has no serious insect or disease problems. The stems may bend and flop over if planted in soil that is too rich or if the plant obtains too little sun.

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.

 

More information on Vernonia lettermannii.

Profile Video:
See this plant in the following landscapes:
Pollinator Garden in Full Sun Pollinator Garden in Partial Shade
Cultivars / Varieties:
Tags:
#cultivars#showy flowers#drought tolerant#fine texture#fast growing#summer flowers#magenta flowers#long bloom time#rock garden#pollinator plant#poor soils tolerant#compact habit#butterfly friendly#perennial#landscape plant sleuths course
 
Cultivars / Varieties:
Tags:
#cultivars#showy flowers#drought tolerant#fine texture#fast growing#summer flowers#magenta flowers#long bloom time#rock garden#pollinator plant#poor soils tolerant#compact habit#butterfly friendly#perennial#landscape plant sleuths course
  • Attributes:
    Genus:
    Vernonia
    Species:
    lettermannii
    Family:
    Asteraceae
    Life Cycle:
    Perennial
    Country Or Region Of Origin:
    Cultivar of a native plant
    Play Value:
    Attractive Flowers
    Attracts Pollinators
    Colorful
    Dimensions:
    Height: 2 ft. 0 in. - 3 ft. 0 in.
    Width: 1 ft. 6 in. - 2 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Herbaceous Perennial
    Perennial
    Habit/Form:
    Dense
    Mounding
    Multi-stemmed
    Growth Rate:
    Rapid
    Maintenance:
    Low
    Texture:
    Fine
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    Clay
    Loam (Silt)
    Sand
    Shallow Rocky
    Soil pH:
    Acid (<6.0)
    Alkaline (>8.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Occasionally Dry
    Available Space To Plant:
    12 inches-3 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Flowers:
    Flower Color:
    Purple/Lavender
    Flower Inflorescence:
    Corymb
    Flower Value To Gardener:
    Long Bloom Season
    Showy
    Flower Bloom Time:
    Summer
    Flower Size:
    < 1 inch
    Flower Description:
    Frilly 1-inch purplish-red disc flowers in terminal corymbs in mid to late summer from July to August.
  • Leaves:
    Leaf Color:
    Green
    Leaf Value To Gardener:
    Showy
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Linear
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    3-6 inches
    Leaf Width:
    < 1 inch
    Leaf Description:
    Attractive linear green leaves spiral alternately up the stem and become denser at the tips. Up to 5 inches long and 1/8 inch wide with smooth margins.
  • Stem:
    Stem Color:
    Green
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Pool/Hardscape
    Slope/Bank
    Landscape Theme:
    Butterfly Garden
    Cottage Garden
    Drought Tolerant Garden
    Pollinator Garden
    Rock Garden
    Design Feature:
    Border
    Attracts:
    Bees
    Butterflies
    Pollinators
    Resistance To Challenges:
    Drought
    Dry Soil
    Erosion
    Poor Soil